Defining and treating high-risk multiple myeloma.

Multiple myeloma (MM) is more recently being recognized as a heterogeneous group of disease with variability in outcomes based on specific clinical and biologic predictors. MM patients can be broadly categorized into standard, intermediate and high risk for disease relapse, morbidity and mortality. The high-risk features include patient-specific factors such as old age, poor performance status and comorbidities; clinical features such as primary plasma cell leukemia and extramedullary disease; disease-specific biologic features such as deletion 17p, t(4;14) and high-risk gene expression profiling signatures. The current paper reviews the available data on best therapeutic approaches for high-risk MM.